Heat
oven to 160C/140C fan/gas 3. Line a muffin tin with 12 muffin cases.
With an electric whisk, whisk the butter, 250g of the sugar, eggs,
flour, zest of 2 lemons and juice from 1 lemon until just combined -
don't over-whisk (3-4minutes only). Divide between the cases (they will be quite full),
then bake on a middle shelf for 30 minutes, until a skewer poked in comes
out clean.

Cool for 10 mins, then transfer cakes to a cooling
rack on a tray and poke each a few times with a skewer. Pour remaining
lemon juice over remaining 150g sugar and zest 1 lemon, and immediately
spoon over the cakes. Leave to cool.